1. Field of the Invention
The present invention relates to improvement of a cylinder-type air damper to be employed, for example, in a glove box of an automobile.
2. Description of Relevant Art
In Japanese Utility Model Registration Publication No. 2557064 a conventional air damper is disclosed.
The typical air damper is composed of a tubular cylinder have two open ends, a piston which is connected to an end of a string for moving in the cylinder, a valve device which is installed at one end of the cylinder for controlling a passing amount of air, a guide cap which is installed at the other end of the cylinder for guiding the string, and a compressed coil spring which is interposed between the guide cap and the piston in the cylinder.
This conventional air damper has the advantage of ensuring smooth opening or closing motion of a glove box. One disadvantage of the typical air damper is that the amount of the string that can be pulled out of the cylinder is limited to the travel distance of the piston in the cylinder. Thus, when used in a place where the cylinder cannot have a large length there is the disadvantage of a very short damper stroke.
An object of the invention is to provide an air damper which allows a longer damper stroke even in an installment with a reduced cylinder space.
In a first aspect of the present invention, there is provided an air damper as follows. In the air damper, a tubular cylinder has a first end and a second end. A piston is movable in the cylinder. A compressed coil spring resiliently biases the piston toward the first end of the cylinder. A string transmits a damper function caused by a movement of the piston to a movable body connected to one end of the string. The string is wrapped partially around the piston and extends the length of the cylinder.
Preferably, the string has a first end fixed to a portion of the body that is movable relative to an air damper body, and a second end fixed to the air damper body or an unmovable portion of the air damper body.
Preferably, the air damper further includes a separating plate at the second end of the cylinder as an entrance and exit for the string. The string extends along both sides of the separating plate.
Preferably, the piston has a hook body formed with a hook wall having a closed annular shape around which the string passes and the piston rotatably supports the hook body.
Preferably, the cylinder is provided with an installment piece fixed to the cylinder, and a second end of the string is provided with a clip, which is engaged with the installment piece and is fixed to the installment piece.
In a second aspect of the present invention, there is provided an air damper as follows. The damper includes a longitudinal cylinder with a first end and a second end; a piston longitudinally movable in the cylinder; and a string which passes over the piston in the cylinder and extends longitudinally along the cylinder.
Preferably, the air damper further includes a spring, which biases the piston toward the first end of the cylinder.
Preferably, the air damper further includes a separating plate at the second end of the cylinder and each end of the string passes along a side of the separating plate.
Preferably, the piston has a rotatably mounted hook body. The string is passed over the hook body.
According to the invention, the movable string passes over the piston, and, compared to conventional dampers, even in a small-sized air damper designed according to the present invention, the amount of the string that can be pulled out of the cylinder is much longer, thus providing the necessary damper stroke.
The first end of the string is fixed to a part that moves relative to the air damper body and the second end is fixed to the air damper body or a part that does not move relative to the air damper body, so that, compared to a typical damper, even in a small-sized air damper designed according to the present invention, the amount of the string that can be pulled out of the cylinder is longer, thus providing the necessary damper stroke.
The separating plate is provided at a second end of the cylinder as an entrance and exit for the string, so that a twist of the string outside the cylinder is prevented from spreading to inside the cylinder, and a twist in the cylinder is adjusted by pulling the string.
The string passes over the closed annular hook wall of the hook body, so that the string cannot come off the hook body, and the hook body rotates relative to the piston to further effectively adjust a twist of the string in the cylinder.
The second end of the string is provided with a clip, and thus the second end of the string is easily connected to an installment piece on a side of the cylinder.